ASA5505# copy running-config tftp
ASA5505# copy running-config tftp ? !--this will allow you to save the running-config to a tftp server. I recommend tftpd32: http://tftpd32.jounin.net/
ASA5505# copy tftp ?
disk0: Copy to disk0: file system
flash: Copy to flash: file system
ftp: Copy to ftp: file system
running-config Update (merge with) current system configuration
smb: Copy to smb: file system
startup-config Copy to startup configuration
system: Copy to system: file system
tftp: Copy to tftp: file system
ASA5505# copy tftp run !--This will merge with the current system. This can be good and or bad. Personally, what I do is get the config the way I like it and create a spreadsheet, define the variables, change them per device and away you go. From this point it is just copy and paste.
Just remember to negate some of the default config such as:
no dhcpd address 192.168.1.2-192.168.1.33 inside
domain-name example.com
aaa authentication ssh console LOCAL
crypto key generate rsa modulus 1024
Reference: http://www.cisco.com/en/US/products/hw/vpndevc/ps2030/products_tech_note09186a008072142a.shtml